Central Weather Administration Wave Data

library(dplyr)
library(ggplot2)
library(readxl)
library(patchwork)

large <- theme(legend.title = element_text(size=15),
        legend.text = element_text(size=15),
        axis.title = element_text(size=15),
        axis.text = element_text(size=15),
        strip.text = element_text(size=15))

rotate <- theme(axis.text.x = element_text(angle = 90, hjust=1))

no_strip <- theme(strip.background = element_rect(colour=NA, fill=NA),
                  strip.text = element_text(colour=NA))

Central Weather Administration Buoy Data

海象資料下載

# Hualien buoy
hua <- read_excel("../Data//2012_46699A_Hualien buoy_wave.xlsx", skip=9)
hua$yyyymmddhhmi <- strptime(hua$yyyymmddhhmi, format="%Y%m%d%H%M") %>% as.POSIXct
hua$Header <- "Hualien buoy"

# Chenggong
che <- read_excel("../Data//2012_46761F_Chenggong_wave.xlsx", skip=15)
che$yyyymmddhhmi <- strptime(che$yyyymmddhhmi, format="%Y%m%d%H%M") %>% as.POSIXct
che$Header <- "Chenggong"
names(che)[4:5] <- c("H", "T")
#che <- che[che$Dif!=0,]
out <- rbind(hua[, c(1:4, 6, 8:11)], che)
names(out)[1] <- "Buoy"
out$Buoy <- factor(out$Buoy, levels=c("Hualien buoy", "Chenggong"))

# Typhoon impact periods
rec <- rbind(c("2012-07-30 00:00", "2012-08-03 23:59"), 
      c("2012-08-05 00:00", "2012-08-07 23:59"),
      c("2012-08-14 12:00", "2012-08-16 23:59"),
      c("2012-08-21 00:00", "2012-08-30 23:59")) %>% as.data.frame
names(rec) <- c("xmin", "xmax")
rec$xmin <- as.POSIXct(rec$xmin)
rec$xmax <- as.POSIXct(rec$xmax)
Typhoon <- factor(c("Saola", "Haikui", "Kai-tak", "Tembin"), levels=c("Saola", "Haikui", "Kai-tak", "Tembin"))
rec <- cbind(rec, Typhoon)

ggplot()+
  geom_rect(data=rec, aes(xmin = xmin, xmax = xmax, ymin=0, ymax=Inf, fill=Typhoon), alpha=0.5)+
  geom_rect(data=rec, aes(xmin = as.POSIXct("2012-08-18 08:00"), xmax = as.POSIXct("2012-08-20 17:00"), ymin=0, ymax=Inf), fill="transparent", colour="red", linetype=2)+
  geom_path(data = out, aes(x=yyyymmddhhmi, y=H/100, group=Grp))+
  facet_wrap(~Buoy, ncol=1, scales="free")+
  labs(x="", y="Significant wave height (m)")+
  scale_x_datetime(limits = as.POSIXct(c("2012-07-28 00:00", "2012-08-31 23:59")), expand = c(0, 0)) +
  scale_y_continuous(expand = c(0, 0)) +
  scale_fill_viridis_d()+
  scale_colour_viridis_d()+
  theme_bw() 

ggplot()+
  geom_rect(data=rec, aes(xmin = xmin, xmax = xmax, ymin=0, ymax=Inf, fill=Typhoon), alpha=0.5)+
  geom_path(data = out, aes(x=yyyymmddhhmi, y=600/T, group=Grp))+
  geom_rect(data=rec, aes(xmin = as.POSIXct("2012-08-18 08:00"), xmax = as.POSIXct("2012-08-20 17:00"), ymin=0, ymax=Inf), fill="transparent", colour="red", linetype=2)+
  facet_wrap(~Buoy, ncol=1)+
  labs(x="", y=expression(Wave~Frequency~(min^-1)))+
  scale_x_datetime(limits = as.POSIXct(c("2012-07-28 00:00", "2012-08-31 23:59")), expand = c(0, 0)) +
  scale_y_continuous(expand = c(0, 0)) +
  scale_fill_viridis_d()+
  scale_colour_viridis_d()+
  theme_bw() 

Typhoon Soala

# Wave height >= 2.5 m
dif <- function(x) max(x)-min(x)
# Hualien buoy
# Persist large wave
subset(hua, yyyymmddhhmi<=as.POSIXct("2012-08-04") & yyyymmddhhmi>=as.POSIXct("2012-07-30") & H>=250)$yyyymmddhhmi %>% dif

## Time difference of 2.083333 days

# Wave frequency 
(600/subset(hua, yyyymmddhhmi<=as.POSIXct("2012-08-04") & yyyymmddhhmi>=as.POSIXct("2012-07-30") & H>=250)$T) %>% mean

## [1] 5.794467

(600/subset(hua, yyyymmddhhmi<=as.POSIXct("2012-08-04") & yyyymmddhhmi>=as.POSIXct("2012-07-30") & H>=250)$T) %>% sd

## [1] 0.7001203

# Chenggong buoy
# Persist large wave
subset(che, yyyymmddhhmi<=as.POSIXct("2012-08-04") & yyyymmddhhmi>=as.POSIXct("2012-07-30") & H>=250)$yyyymmddhhmi %>% dif

## Time difference of 3 days

# Wave frequency 
(600/subset(che, yyyymmddhhmi<=as.POSIXct("2012-08-04") & yyyymmddhhmi>=as.POSIXct("2012-07-30") & H>=250)$T) %>% mean

## [1] 7.792122

(600/subset(che, yyyymmddhhmi<=as.POSIXct("2012-08-04") & yyyymmddhhmi>=as.POSIXct("2012-07-30") & H>=250)$T) %>% sd

## [1] 1.161305

limits <- subset(out, yyyymmddhhmi<=as.POSIXct("2012-08-04") & yyyymmddhhmi>=as.POSIXct("2012-07-30") & H>=250)$yyyymmddhhmi %>% range

ggplot()+
  geom_rect(data=rec, aes(xmin = xmin, xmax = xmax, ymin=0, ymax=Inf, fill=Typhoon), alpha=0.5)+
  geom_rect(data=rec, aes(xmin = as.POSIXct("2012-08-18 08:00"), xmax = as.POSIXct("2012-08-20 17:00"), ymin=0, ymax=Inf), fill="transparent", colour="red", linetype=2)+
  geom_path(data = out, aes(x=yyyymmddhhmi, y=H/100, group=Grp))+
  facet_wrap(~Buoy, ncol=1, scales="free")+
  labs(x="", y="Significant wave height (m)")+
  scale_x_datetime(limits = limits, expand = c(0, 0)) +
  scale_y_continuous(expand = c(0, 0)) +
  scale_fill_viridis_d()+
  scale_colour_viridis_d()+
  theme_bw() 

ggplot()+
  geom_rect(data=rec, aes(xmin = xmin, xmax = xmax, ymin=0, ymax=Inf, fill=Typhoon), alpha=0.5)+
  geom_path(data = out, aes(x=yyyymmddhhmi, y=600/T, group=Grp))+
  geom_rect(data=rec, aes(xmin = as.POSIXct("2012-08-18 08:00"), xmax = as.POSIXct("2012-08-20 17:00"), ymin=0, ymax=Inf), fill="transparent", colour="red", linetype=2)+
  facet_wrap(~Buoy, ncol=1)+
  labs(x="", y=expression(Wave~Frequency~(min^-1)))+
  scale_x_datetime(limits = limits, expand = c(0, 0)) +
  scale_y_continuous(expand = c(0, 0)) +
  scale_fill_viridis_d()+
  scale_colour_viridis_d()+
  theme_bw() 

Typhoon Haikui

# Wave height >= 1.5 m
# Hualien buoy
# medium wave (h)
subset(hua, yyyymmddhhmi<=as.POSIXct("2012-08-07 23:59") & yyyymmddhhmi>=as.POSIXct("2012-08-05 00:00") & H>=150)$H %>% length/subset(hua, yyyymmddhhmi<=as.POSIXct("2012-08-08 23:59") & yyyymmddhhmi>=as.POSIXct("2012-08-05 00:00"))$H %>% length * 72

## [1] 9.75

# Chenggong buoy
# medium wave (h)
subset(che, yyyymmddhhmi<=as.POSIXct("2012-08-07 23:59") & yyyymmddhhmi>=as.POSIXct("2012-08-05 00:00") & H>=150)$H %>% length/subset(che, yyyymmddhhmi<=as.POSIXct("2012-08-08 23:59") & yyyymmddhhmi>=as.POSIXct("2012-08-05 00:00"))$H %>% length * 72

## [1] 12.18898

ggplot()+
  geom_path(data = subset(out, yyyymmddhhmi<=as.POSIXct("2012-08-07 23:59") & yyyymmddhhmi>=as.POSIXct("2012-08-05 00:00")), aes(x=yyyymmddhhmi, y=H/100, group=Grp))+
  facet_wrap(~Buoy, ncol=1, scales="free")+
  labs(x="", y="Significant wave height (m)")+
  scale_x_datetime(expand = c(0, 0)) +
  scale_y_continuous(expand = c(0, 0)) +
  scale_fill_viridis_d()+
  scale_colour_viridis_d()+
  theme_bw() 

ggplot()+
  geom_path(data = subset(out, yyyymmddhhmi<=as.POSIXct("2012-08-07 23:59") & yyyymmddhhmi>=as.POSIXct("2012-08-05 00:00")), aes(x=yyyymmddhhmi, y=600/T, group=Grp))+
  facet_wrap(~Buoy, ncol=1)+
  labs(x="", y=expression(Wave~Frequency~(min^-1)))+
  scale_x_datetime(expand = c(0, 0)) +
  scale_y_continuous(expand = c(0, 0)) +
  scale_fill_viridis_d()+
  scale_colour_viridis_d()+
  theme_bw() 

Typhoon Kai-tak

# Wave height >= 1.5 m
# Hualien buoy

# small wave (h)
subset(hua, yyyymmddhhmi<=as.POSIXct("2012-08-16 23:59") & yyyymmddhhmi>=as.POSIXct("2012-08-14 12:00") & H>=100)$H %>% length/subset(hua, yyyymmddhhmi<=as.POSIXct("2012-08-17 23:59") & yyyymmddhhmi>=as.POSIXct("2012-08-14 00:00"))$H %>% length *60

## [1] 4.375

# Chenggong buoy
# medium wave (h)
subset(che, yyyymmddhhmi<=as.POSIXct("2012-08-16 23:59") & yyyymmddhhmi>=as.POSIXct("2012-08-14 12:00") & H>=150)$H %>% length/subset(che, yyyymmddhhmi<=as.POSIXct("2012-08-17 23:59") & yyyymmddhhmi>=as.POSIXct("2012-08-14 00:00"))$H %>% length *60

## [1] 4.090909

subset(che, yyyymmddhhmi<=as.POSIXct("2012-08-16 23:59") & yyyymmddhhmi>=as.POSIXct("2012-08-14 12:00") & H>=100)$H %>% length/subset(che, yyyymmddhhmi<=as.POSIXct("2012-08-17 23:59") & yyyymmddhhmi>=as.POSIXct("2012-08-14 00:00"))$H %>% length *60

## [1] 31.09091

ggplot()+
  geom_path(data = subset(out, yyyymmddhhmi<=as.POSIXct("2012-08-16 23:59") & yyyymmddhhmi>=as.POSIXct("2012-08-14 12:00")), aes(x=yyyymmddhhmi, y=H/100, group=Grp))+
  facet_wrap(~Buoy, ncol=1, scales="free")+
  labs(x="", y="Significant wave height (m)")+
  scale_x_datetime(expand = c(0, 0)) +
  scale_y_continuous(expand = c(0, 0)) +
  scale_fill_viridis_d()+
  scale_colour_viridis_d()+
  theme_bw() 

ggplot()+
  geom_path(data = subset(out, yyyymmddhhmi<=as.POSIXct("2012-08-16 23:59") & yyyymmddhhmi>=as.POSIXct("2012-08-14 12:00")), aes(x=yyyymmddhhmi, y=600/T, group=Grp))+
  facet_wrap(~Buoy, ncol=1)+
  labs(x="", y=expression(Wave~Frequency~(min^-1)))+
  scale_x_datetime(expand = c(0, 0)) +
  scale_y_continuous(expand = c(0, 0)) +
  scale_fill_viridis_d()+
  scale_colour_viridis_d()+
  theme_bw()